Erratum in

Proc Natl Acad Sci U S A. 2013 Jul 9;110(28):1660-1.

Abstract

During social interactions we automatically infer motives, intentions, and feelings from bodily cues of others, especially from the eye region of their faces. This cognitive empathic ability is one of the most important components of social intelligence, and is essential for effective social interaction. Females on average outperform males in this cognitive empathy, and the male sex hormone testosterone is thought to be involved. Testosterone may not only down-regulate social intelligence organizationally, by affecting fetal brain development, but also activationally, by its current effects on the brain. Here, we show that administration of testosterone in 16 young women led to a significant impairment in their cognitive empathy, and that this effect is powerfully predicted by a proxy of fetal testosterone: the right-hand second digit-to-fourth digit ratio. Our data thus not only demonstrate down-regulatory effects of current testosterone on cognitive empathy, but also suggest these are preprogrammed by the very same hormone prenatally. These findings have importance for our understanding of the psychobiology of human social intelligence.

(A) Effect of testosterone administration on cognitive empathy in young women: mean and SEM of the percentage correct responses on the RMET after administration of testosterone and placebo (P = 0.013, one-tailed). Testosterone administration impairs the ability to accurately infer motives, intentions, thoughts, and emotions from the eye region of the face of others. (B) Fetal testosterone exposure (inferred from 2D:4D ratio) predicts the effect of testosterone administration on cognitive empathy: scatter plot shows the interaction between the 2D:4D ratio fetal testosterone marker and the effect of testosterone (T) administration on cognitive empathy (P < 0.001). The group effect of testosterone administration on cognitive empathy varies strongly according to individual 2D:4D ratios. (C) Effect of testosterone (T) administration on cognitive empathy in subjects with high and low fetal testosterone exposure (inferred 2D:4D ratio): Mean and SEM of the effect of testosterone administration on cognitive empathy in subjects with relatively low and high 2D:4D ratios, based on median split. Substantial effects of testosterone on cognitive empathy are observed in subjects with high fetal testosterone exposure (P = 0.006, one-tailed), and no effects are seen in subjects with low fetal testosterone exposure (P = 1).